Chemical thinning affects yield and return flowering in 'Jubileu' peach

Abstract

Peach hand thinning improves fruit quality; however, it requires a high demand of labor and increases production costs. The objective of this study was to evaluate the effect of growth regulators applied at post-flowering as an alternative to hand thinning of peaches. The experiment was conducted with peach cultivar Jubileu, in 2012. The treatments consisted of no thinning, hand thinning 45 days after full bloom (DAFB), ethephon (85 and 120 mg L-1), benzyladenine (BA) (400 mg L-1), and BA plus gibberellic acid (GA4 + 7) (400 mg L-1) applied 40 DAFB. BA-treated plants were not different from non-thinned plants, had excessive load, and smaller diameter fruit. Treatment with ethephon at 120 mg L-1 resulted in excessive thinning and decreased yield in comparison with other treatments. Plants treated with 85 mg L-1 ethephon and BA + AG4 + 7 (400 mg L-1) had fruit abscission, crop load, production per plant and fruit diameter similar to hand-thinned plants. In 2013, an increased number of flower buds was observed in treatments with ethephon and also reduction of this trait in BA and BA + GA4 + 7 applications. Ethephon at 85 mg L-1 can be an alternative of chemical thinning in 'Jubileu' peaches, without compromising the return of flower bud numbers in the next crop.

Influence of the Period of Peach Tree Chemical Thinning on Fruit Quality

“…Peach tree cultivars exhibit high bloom, a fact that results in an excessive number of fruits which is incompatible with the production capacity of the plant (Giovanaz et al, 2016;Barreto et al, 2018). The excessive number of fruits leads to small fruits that have low commercial value (Giovanaz et al, 2016).…”

“…Peach tree cultivars exhibit high bloom, a fact that results in an excessive number of fruits which is incompatible with the production capacity of the plant (Giovanaz et al, 2016;Barreto et al, 2018). The excessive number of fruits leads to small fruits that have low commercial value (Giovanaz et al, 2016). In order to improve the quality of fruits and increase their commercial value, thinning must be carried out in the orchard (Greene & Costa, 2013;Turk et al, 2014).…”

“…However, few have shown satisfactory thinning effects. In order to carry out chemical thinning of peach trees, some products, such as 6-benzyladenine, gibberellins, ethylene and metamitron (Meitei et al, 2013;Giovanaz et al, 2014;Giovanaz et al, 2016;Farias et al, 2017;Barreto et al, 2018), have been investigated. Metamitron may be an efficient alternative to peach tree thinning (McArtney et al, 2012).…”

Chemical thinning of flowers and fruits of the peach cultivar Coral with hydrogen cyanamide

“…The lower number of fruits in the plant enables production of fruits with a higher mean mass due to the increased availability and allocation of nutrients to each fruiting organ (GIOVANAZ et al, 2016). VEGO et al (2010) reported that a decrease in the number of fruits reduced competition for carbohydrates, thereby, improving the distribution of assimilates resulting in fruits with larger mass, diameter, and length.…”

“…Thinning technique aims to remove excess fruitlets from the trees to increase the fruit size, color and quality. Thinning also helps to minimize or eliminate alternate bearing and branch breaking, while decreasing the number of defective fruits and minimizing harvesting costs (GIOVANAZ et al, 2016). SOUZA et al (2013SOUZA et al ( , 2017 reported that some peach cultivars develop alternate production, with variable yield over consecutive years, which may be minimized by adopting methods that regulate the fruit load of peach trees.…”